Just get mags and spend the rest on good boots, eye pro, gloves... etc. No point in having a pimped out gun, playing in your old running shoes then having to quit after an hour because you ran through a few puddles and now have blisters the size of your brand new red dot sight on your heel....

After you have the essentials, then start thinking accessories.

Fully agree with above.
Oder of priority should be

eyepro (no Korean knock offs) since nobody will let you play without.

Decent boots. These will pay for themselves with the decreased chance of foot problems, ankle injuries, etc.